The law firm Jenner and Block filed suit against the Trump Administration Friday seeking to block an executive order signed by President Donald Trump last week that targeted its attorneys’ security clearances and essentially shuttered any interactions with the federal government.

“The Order threatens not only Jenner, but also its clients and the legal system itself,” the firm said Friday in its lawsuit. “Our Constitution, top to bottom, forbids attempts by the government to punish citizens and lawyers based on the clients they represent, the positions they advocate, the opinions they voice, and the people with whom they associate.”

Jenner and Block is now the second of five firms targeted by Trump to bring a legal challenge against what it describes as a blatantly “unconstitutional” executive order, following a successful effort by the law firm Perkins Coie to have a federal judge temporarily block a similar order that targeted it over its representation of then-candidate Hillary Clinton’s 2016 presidential campaign.

The lawsuit, filed in federal court in D.C. Friday, accuses the Trump Administration of engaging in a sweeping campaign to intimidate major law firms that either represented or once counted among its ranks individuals who he has labeled his political enemies.

“These orders send a clear message to the legal profession: Cease certain representations adverse to the government and renounce the Administration’s critics — or suffer the consequences,” the suit said. “The orders also attempt to pressure businesses and individuals to question or even abandon their associations with their chosen counsel, and to chill bringing legal challenges at all.”

The filing comes amid a crisis that has gripped other “Big Law” firms in Washington, as top attorneys debate whether to fight back, cut a deal or stay quiet wondering whether they will be singled out next.

On Thursday, Trump signed another executive order targeting WilmerHale — citing its hiring of former Special Counsel Robert Mueller and two of his top deputies, after they had investigated the 2016 Trump campaign’s ties to Russia.

In a statement reacting to the order, a spokesperson for WilmerHale said they planned to pursue “all appropriate remedies to this unlawful order.”